WO 97/43052 discloses a primer selection method using a grey primer having a reflectance in its dried state which is the same as the reflectance of the top coating measured at the wavelength of minimum absorption of the top coating. Only the grey tone of the primer is adapted to the base coat colour.
Further, it is known to use coloured primers, such as the Colorbuild® primers marketed by Akzo Nobel Coatings, Sassenheim, the Netherlands. A primer is selected which has a colour matching, to some degree, the colour of the object to be repaired. Subsequently, a top or base coat can be applied which matches the colour of the car to be repaired. Due to the close colour match of the primer, a reduced amount of top coat or base coat is needed. A drawback to this system is that there is only a limited number of primer colours available. This limited number of available colours, however, still requires considerable storage space.
U.S. Pat. No. 4,552,780 discloses a method for application of a top coat at incomplete hiding over a colored intercoat. No suggestion is included to select a combination of a primer and a base or top coat matching together an original colour of an object to be repaired.